Sulfonation of propylene trimer and tetramer



r 2,810,746 l Patented Oct. 22, 1957 SULFONATION F PROPYLENE TRIlVlER AND TETRAMER Walter H. C. Rueggeberg, Atlanta, and Thomas W. Sauls, College Park, Ga., assignors to Tennessee Corporation, New York, N. Y., a corporation of New York No Drawing. Application April 8, 1955, Serial No. 500,294

3 Claims. (Cl. 260-513) This invention relates to the sulfonation of propylene trimer and tetramer and to the resultant sulfonated materials which together with their salts have valuable surface active properties.

Because of their surface active properties and extended use as wetting, rewetting, emulsifying, dispersing and similarly used agents in the textile as well as in numerous other industries, sulfonated oils have been known and manufactured for a long time. In prior patents and literature pertaining to this subject, however, the term sulfonated often has been erroneously applied to materials which are the addition products of sulfuric acid to an ole- ,finic linkage or the reaction product of an alcohol with a sulfating agent such as H2504, oleurn, 503, or ClSOsH. These latter types of materials are really esters of sulfuric acid, i. e., they are sulfates rather than sulfonates, the latter term being properly applied only to those materials containing a direct carbon to sulfur linkage. These two types of materials can be represented by the following formulae: 7

The alkyl sulfuric acids, or sulfates, are soluble in water, and if the hydrocarbon part of the molecule is "sufiiciently large (C8 to C20), exhibit surface activity.

For example, treatment of olefinic bodies with sulfuric acid forms addition products of H2804 at the olefinic linkage, as in the case of sulfated esters of unsaturated fatty acids such as propyl oleate.

' heat:

These decompositions often become troublesome when sulfated materials have to be stored in considerable quantities before shipment or use. Furthermore, when sulfuric acid or oleum is used as a sulfating agent for olefins, an excess of the sulfating agent is required to obtain practical yields of the sulfated product in most instances. When neutralized, this excess becomes sodium sulfate which is undesirable in many cases, but it is difficult-and costly to remove either the excess sulfuric acid from the unneutralized sulfated product or the NaaSOr from the neutralized sulfated product.

A much more desirable configuration for these types of materials is that where true sulfonation exists, that is, where there exists a carbon to sulfur linkage of type (2), because hydrolysis of the sulfonic acid or its salts is impossible under nearly all conditions of acidity and basicity and over a wide temperature range. Thus it has been proposed to produce stable carbon to sulfur linkages at the double bond of unsaturated materials by means of the well known carbyl sulfate reaction. This reaction, in order to obtain a high yield, requires at least two moles of S03 per mole of unsaturated material. Carbyl sulfate formation can be expressed as follows:

The carbyl sulfate can then be hydrolyzed to give a sul fonic-acid sulfuric acid ester as follows:

do. as a... (s

- (l -8'0. on so:

Under more vigorous conditions the sulfonate-sulfate grouping can be further hydrolyzed to a hydroxy-sulfonic It will be seen that products of types (4), (5), and (6) each contain a carbon to sulfur linkage, but also that addition has taken place at both carbon atoms at the double bond, requiring two moles of S03, and that unsaturation has disappeared. These products and their sodium and other salts possess surface activity and wetting properties, but in general are inferior in these respects to well known and widely used sulfated oils (e. g., Twitchell oils), while their preparation is more complex and excessive amounts of sulfonating agent are required.

One of the objects of the present invention is to sulfonate olefinic bodies, particularly those described hereinafter, so as to produce sulfonic or carbon-to-sulfur linkages between one of the carbon atoms at the double bond and the sulfonic acid group SO3H, and to eliminate largely the carbyl sulfate reaction set forth above and minimize the formation of sulfuric acid esters and hydroxy sulfonates. The primary reaction taking place can be expressed as follows:

H SOzOH In recent years, a large number of liquid hydrocarbon raw materials have been produced cheaply by the catalytic polymerization of lower molecular weight monomers. For example, propylene prepared by high temperature dehydration of propane will polymerize under the influence of catalysts such as H3PO4 and H2504 to yield products containing three and four propylene units and therefore called propylene trimer and tetramer respectively. Since they contain nine and twelve carbon atoms respectively and only one double bond per molecule, they are also sometimes called nonene and dodecene, but actually they are rather complex mixtures of olefins averaging C9 and C12 respectively in their chains. Published data indieate thepresence of a -num'ber of strhcfui having a i double-bond and in some-cases also a'reactive tertiary hydrogen atom, i. e., a hydrogen atom attached to a carbon atom which in turn is attached to three othercarbon atoms- We have found-that *when propylene-tiinierand/or tetra mer as I described above are sulfonatedby't reatment with sulfur trioxidetSOg) in-liqu-idsulfur dioxide (SO 2) in-the presence of a small-amount of acetic acid catalyst; the abveprimary Reaction 7 is obtained. In addition to this primary reactio nQSOsH may also replace some allylic hydrogenin the position indieated in the-follow- The sulfate groupthus formed is very unstable. and hence may decompose to give rise to the following reaction:

I 080311 E H SOaH 0H Hydroxy sulfonic acids can be formed also through the addition of the intermediate product of Formula 9 to the double bond as follows:

.The'reaction can be carried out in anydesired manner. For example, propylene, trimer and/ or tetramer is--mixed with appropriate quantities of the sulfonatingagent' (i.;-e., S03 dissolved in liquid S02) and of the carboxylic'catalyst either batchwise or continuously. have been obtained by supplying these reagents continu-' 'ously and at equivalent rates to a' spinning disk so that discharged from the disk by centrifugal force. The reaction is essentially instantaneous andtakes place rapidly at the temperature of liquid S02 under atmospheric pres- .sure, say l0 0. Hence the use of higher temperatures ,and'pressure-equipment are unnecessary.

The amount of S03 should preferably be about one mole per-mole olefin as aminimum in order to obtain good ',-yields and a high' degree of monosulfonation at the double .bond. At this ratio of the reagents, the following typical examples indicate that the molar ratio of combined S03 Good results Bf type 7 set forthabove with or without acetic acid catalyst. The amount of S03 may be increased if desired, say up to about two moles per mole of olefin, with an accompanying increase in the amount of olefin converted to sulfonated material as would be expected. It is found, however, that under the-conditions of the reaction the excess S03 causes very little increase in carbyl sulfate formation, even-in the absence of acetic acid catalyst. Instead the residual unsaturationis largely retained and thereislittleincrease .in-thepercentage of hydroxy sulfonate, these results indicating a considerable amount of allylic or tertiary hydrogen sulfonation.

The acetic acid is not combined in the end product T but remains free andcan be titrated in'the sulfonic-acetic acid reaction mixture. The amount of this acetic acid catalyst should not be substantially less than 0.125 mole per mole of S03 used in the reaction, which appears to be about the minimum effective concentration. It will be understood that larger concentrations can be used as pointed out below. At thisminimum concentration, however, acetic acid causes an increase of about 15% or more in the weight percent of olefin converted to sulfonated material, using one mole S03 per mole of olefin. At higher ratios of S03 to olefin and in-the presence of'excess S03, the extent of this increase may be reduced, as it was in the case of propylene trimer (Table III). use of acetic acid also causes a small decrease in the amount of residual unsaturation and an accompanying increase in the amount of hydroxy-sulfonate due to reaction ll set forth above. i

In the following illustrative examples, 'trimer and tetramer had the following characteristics:

Propylene trimer:

Average molecular wt 126. Sp. gr 0.74 g./ml.' Sulfur 20.0 p. p.m..

Unsaturates as C9H1s 95 mole percent. Propylene tetramer:

V F.'. Sulfur"; 0.1 weight percent, max. Bromine number .85-115. 5

Distillation, 5% min 375F.

over the outside ofthe flask while stirring the contents.. This evaporation'time varied from 10-20 minutes. Ad-

dition of' 25 ml. water was made in 'all"cases*when the temperature of the acid reached 23-25 C; Hydrolysis "caused the temperature to rise to 5065 "C., depending to olefin willusually'be about 1.0 and that about 80 mole percent or'more of the'unsaturation existing prior to sulitonati n ta n shqwi sth t t ert mry I 91li upon the amount of S03 usedin excess of olefin. Strip- 7 ping of the S02 was virtually complete after 15 minutes of stirring the warm hydrolyzed acid with air sweeping through the-flask 'over'but not through the liquidcontents, Neutralizations were made by adding a 25% NaOH solution while allowing thetemperature torise at Willto 90 C. The slightly basic (pH 940) solutions were then boiled gently for 1% hours with reflux to hydrolyze the. ester groups present. Small additions of NaOH solution during this time were made since the pH wasobserved to drop during the hydrolysis. Final pH was left .at 9-10. f After cooling and diluting with cold water toapproximately, 30-35% solids, the oil was extracted from'the aqueous' solutions with three ,110 mli portions of petrole- V ether (3,. P. 30-65 T 0.). V Inseveral-instances,addi- The V the propylene tion of a few ml. of methanol was found to be necessary to break the emulsions.

After boiling E the residual petroleum ether and methanol from the aqueous solutions, the total runs were bottled and weighed accurately.

The approximate conversion was found by evaporation of the combined petroleum ether extracts on a water bath. However, due to the slight volatility of the oil at this temperature and to the reluctance of the higher boiling ether fractions to be driven oif, only rough conversion figures could be obtained in this manner.

Analyses and evaluations'of the products, where performed, were made by the following procedures:

Percent solids:

(a) Toluene distillation method whereby a 20.0 g. sample plus 70 ml. toluene gave the measured quantity of water.

([1) Drying method whereby a 10 g. sample was weighed to 0.01 g. in an evaporating dish, left in the oven at 110 C. overnight, and weighed again. This method gave slightly lower results than (a).

Percent inorganics: Methanol precipitation method was used whereby a 10.0 g. sample was taken. 18 ml. H2O plus 250 ml. MeOH was added with stirring. The inorganic salts were filtered off, washed with 90% MeOH, dried at 110 Cffor at least 1 hour, and weighed on the tared filter paper.

Percent organic salts by difference. 7

Percent sodium acetate by calculation.

Mercerization test (performed on tripropylene sulfonate only): 0.6 g. active ingredient was added to 600 g. 25% NaOH solution to make 0.1% active solution. A Draves wetting test with a heavy (4.5 g.) hook at 7 30 C. was then performed on each sample.

Degree of residual unsaturation after sulfonation (performed on tripropylene sulfonate only): A direct titration of the extracted aqueous solutions with bromine in glacial acetic acid was used for these determinations.

Approximately 1 gram of the 25-30% aqueous solutions were weighed duplicate in ground glass stoppered bottles. Afteradding l ml. glacial acetic acid to the samples the bottles were cooled in the refrigerator just short of the freezing point of acetic acid. The samples were then titrated rapidly with 0.3 N bromine in acetic acid tothe first yellow color persisting for at least seconds. Samples 2, 3, 5, 6 of the tripropylene sulfonate developed a blue color upon adding the first bromine making it necessary to titrate to a green end point which was not as satisfactory as samples 1 and 4. (This same method gave 87% unsaturation as nonene when applied directly on the unsulfonated tri propylene. A small amount of HBr was observed in this analysis whereas in the analyses of the aqueous sulfonated samples no I-IBr was observed.)

Percent hydroxy sulfonate: The acetylation method using acetic anhydride and pyridine as described in Siggias Quantitative Organic Analysis via Functional Groups (page 5) was employed. Water was removed from 10 gram aqueous samples by distilling with ml. toluene in the usual water trap apparatus. After removing the water, all but 10 ml. of the toluene was then distilled off. To these dehydrated samples in toluene was added 5 ml. of acetic anhydride-pyridine mixture (10 ml. acetic anhydride plus 30 ml. pyridine). The flasks, with pyridine-moistened glass stoppers inserted, were then heated on a water bath for minutes at which time 10 ml. of water was added and heating was continued for two more minutes. After cooling, the samples were then titrated with 0.5 N alcoholic NaOH to the blue color of cresol red-thymol blue indicator. Blanks containing toluene and acetic anhydride-pyridine mixture were run along with all the samples. In addition to this blank an acid-alkalinity blank on a separate dehydrated sample of sulfonate such as described above, was determined and found to be nil in all six cases.

TABLE I Materials required for the sulfonation oftripropylene S03 Olefin Acetic Acid Mole N aOH Run No. ratio, S03

gms. moles gms. moles gms. moles Olefin gms. moles TABLE II Composition and properties of aqueous sulfonuted tripropylene solutions Extrd Weight Percent. Solids 1 Mercerizg Avg. 2 Mole Oil Extrd Percent Gardner Test ml. per- Percent Run N0. (g'ms) Prod. Inorg. Color (seconds) cent of Nonene (a) (b) Residl Hydroxy Unsatn Sulfonate 411. 0 32. 5 a1. 9 4. 93 8 9 9 78.8 3. 9 358. 7 31. 2 30. 3 7. 72 10 9 72. 4 4. 9 343. 5 30.0 29. 3 9. 3 13 13 68. 8 5. 8 423. 5 26. 7 26. 1 5. 33 9 9 83. 5 nil 377.0 26. 2 24. 5 '8. 39 .10 15 77 1. l 334. 0 28. 8 27. 9 9. 78 12 15 74. 5 4. 5

1 (a) By distillation method; (5) By 2 Expressed as mole percent nonene s drying method. 7 For details, see above. ulionate. Molecular weight of nonene sodium sulionate taken as 228.

. Total solids in aqueous products ri).

. Inorganic salts in aqueousproduct (gins);

. Sodium acetate in aqueous product (gms'). Organic salt (active ingredient by difierence) in. aqueous product (gms). E. Wt. SO NaJgroup inactive ingredient by N aOH balance (gins).

' F. Wt. combined olefin by difference (gms).

G. Conversion of olefin (weight percent).

H. S03 lost or unaccounted for (mole percent).

1. Ratio of $03 to combined olefin (molar).

Column G of Table III shows that the yieldof monosulfonated nonene increased in the presence of acetic acid (runs 1, 2 and 3) over those runs where acetic acid is absent (4, 5 and'6).

The amount of S03 unaccounted for as given in column H of Table III wa undoubtedly lost to the fvent. In' larger operations, where closer control can be exercised, this loss would probably not occur.

The ratios of combined moles otSOa to moles olefin (-nonene in this case) are indicative of the fact that the major sulfonation process isfone of monosulfation. According to the last .two columns of Table H, the degree of total monosulfonation (combined unsaturated sulf onate plus hydroxy sulfonate) is at least 70 to 80%.

'8 TABLE vi :Run G Micros-1' H 99 99 7 A. Total solids in aqueous product (gms.). B. Inorganic salts in aqueous product (gIIJS.). 0. Sodium acetate in aqueous product (gms.). 1). )Organic salt (actlve'ingredient by difierence) in aqueous product gins.

E. Wt. SOzNa group in active ingredient by NaOH balance (gins) F. Wt. combined olefin by difierence (gins).

G. Conversion of olefin (weight percent). H. S03 lost or unaccounted for (mole percent). *1; Ratio of S03 to combined olefin (molar).

In addition to the evaluations given in the tables,

above, a few miscellaneous :evaluations were made as follows to show theefiectiveness of sodium tetrapropylene sulfonate:

fertilizer animoniating solution (East Point P1ant) S sec. p Wetting time (Draves) of 0.1% active ingredient in H2SO4=,l.5;sec. 5 1

The data and results presented above show. that both propylene trimer. and propylene tetrame'rcan .be sulfo-.

' nated with SO 3 in S02 in yields of 75-80% and -75%;

respectively,- when 0.125 mole of g'lacia'l' acetic acid per mole of sulfur trioxide is used as catalyst.

Materials required for the' su lfonaiio'ii offeti'api'opylene S0 7 Olefin Acetic Acid ,Mole NaOH Run Ratio, S03

No. 1 to' lefin gins. moles gins. moles .gms. .moles a ,gmS. moles 53.6 0.67 112.5 0.67 i 5 0.083 1.1 30.4' 0.76 53. '6 0. 67 75 0. 447 5 v 0. 083 1. 5-1 29. 3 .0. 73 253.6 .0. 67 -56.--3 0.335 5- 0.083 2-1 28.2. .0.71' d TABLE V Composition and properties ofaqz eozts szzlfoniat'ed tetrapropylene solutions 1(a) By distillation 7666606,- 0 i 661- 6616 6651. For details,

see above.

{approximately 01% activelngredient irndistilled water. j; V I Y conclusively'iit'haflioiiithe' average, '1 mole of S03 isIcomi binedgwith 'l'mole ofolefin to form a stable unsaturated sulfonic acid iii tion is not the primary reaction.

Unsaturation determinations further show (Table H) that after sulfonation the unsaturation is largely retained (68.8 "to 783.5 thus indicating that carbyl sulfate forma- Furthermore, the presence of: acetic acid catalyzes or promotes the reaction 'to a degree such-that an increase of as much as 16.6%

g (runs 1 and 4, column G, Table III) of the monosultonated-product; can'beattributed'to the presence 0t /5 moleof acetic acidperinole of S03.

'A-nalytical-results (column I, Tables III and VI) prove The presence of catalyzed 'sulfon'ations exceeds the amount present 111 hydroxy-sulfonate the acetic-acid.

those runs where acetic acid was absent, as shown by the following results extracted from Table II:

Since the mole ratio of $03 to olefin is constant in runs 1 and 4, 2 and 5, and 3 and 6, the increase in hydroxysulfonate in runs 1, 2 and 3 over that in 4, 5 and 6, respectively, must be attributed to the presence of acetic acid (see Formula II) whereas, in runs 5 and 6 the major portion of the hydroxy-sulfonate formed must be attributed to carbyl-sulfate type intermediates.

Doubling the ratio of S03 to olefin increases the total conversion of the olefin as stated above; for example, compare runs 1 and 3 where the increase amounted to about 12% (column G of Table III). At the same time the amount of residual unsaturation was reduced (Table II), but the amount of hydroxy-sulfonate increased only about 2% as shown above. These facts indicate that excess S03 in this case caused mainly a substitution reaction of tertiary or allylic hydrogen rather than carbyl sulfate formation, and the presence of up to 80+ mole percent of unsaturation in the sulfonated product together with the fact that glacial acetic acid aids in the formation of a small but detectable quantity of hydroxy-sulfonates support the theory illustrated by Formulae 9, 10 and 11.

From the above data, it can be concluded that the monosulfonated propylene polymers consist approximately of the following:

TABLE VII Moles Conver- Mole Ratio,

sion of S03 to Olefin, wt. Combined S03 Olefin Acetic Percent Olefin Acid N era-First two runs from Table D1.

It is evident from the above results that increasing the amount of acetic acid up to about 0.5 mole per mole of S03 causes corresponding increases in the wt. percent of olefin converted to sulfonated product. As will be seen, the conversion is practically complete in the neighborhood of 0.5 mole acetic acid so that further increase in the amount of acetic acid is of no advantage.

On the other hand the above data indicate that such higher amounts of acetic acid cause some polymerization to take place. It will be observed that whereas the conversion of olefin increases as already stated, the mole ratio of $03 to combined olefin decreases at the same time. In other words, the amount of hydrocarbon attached to S03 is greater than in sulfonated nonene per se, and the amount of nonene consumed is also greater, indicating that higher amounts of acetic acid tend to cause to some extent the further polymerization of nonene along with simultaneous sulfonation.

The sulfonated propylene trimer and/or tetramer provide valuable surface active agents as indicated by the evaluations set forth above. They are especially valuable, in the form of their sodium salts, for use in alkaline solutions in which they exhibit extremely good surface activity. For example, the nonene sulfonate is very good in caustic solutions up to at least 30% to 50% concentration, and the tetramer sulfonate in, say, below 20% solutions. It will be understood that the same thing is true as to electrolyte solutions in general at similar concentrations.

It will be understood that the invention is not restricted to the details of the foregoing description and that reference should be had to the appended claims for a definition of its What is claimed is:

1. A process for the sulfonation of propylene trimer and propylene tetramer which comprises sulfonating said propylenic material with sulfur trioxide dissolved in liquid sulfur dioxide in the presence of a quantity of acetic acid catalyst within the approximate proportions of 0.125-0.5 mole of said acid per mole of sulfur trioxide.

2. A process as defined in claim 1, the amount of said sulfur trioxide being in the range of 1.0-2.0 moles per mole of said propylenic material.

3. Sulfonated propylenic material of the group consisting of sulfonated mono-olefinic propylene trimer and propylene tetramer averaging nine carbon atoms and twelve carbon atoms respectively and prepared by the process defined in claim 1, said sulfonated material containing about 69-79% monosulfonated olefin retaining its unsaturation, about 4-6% saturated hydroxy-sulfonate, and about 17-25% saturated sulfonate-sulfate.

References Cited in the file of this patent UNITED STATES PATENTS 2,195,581 Ross Apr. 2, 1940 2,413,199 Taylor Dec. 24, 1946 2,572,605 Fincke Oct. 23, 1951 2,600,415 Mikeska June 17, 1952 

1. A PROCESS FOR THE SULFONATION OF PROPLYENE TRIMER AND PROPYLENE TETRAMER WHICH COMPRISES SULFONATING SAID PROPYLENIC MATERIAL WITH SULFUR TRIOXIDE DISSOLVED IN LIQUID SULFUR DIOXIDE IN THE PRESENCE OF A QUANTITY OF ACETIC ACID CATALYST WITHIN THE APPROXIMATE PROPORTIONS OF 0.125-0.5 MOLE OF SAID ACID PER MOLE OF SULFUR TRIOXIDE. 